So...keep the defective one in? Or put the 180 I am having overnighted from rovor north in.

 

if you bought put it in it will not hurt the Discovery. But do not expect a big change. Your car will pump heat a little sooner. You dont have to worry about it failing..

Make sure your clamps are snug and then climb a freaking mountain.

 

if you bought put it in it will not hurt the Discovery. But do not expect a big change. Your car will pump heat a little sooner. You dont have to worry about it failing..

Make sure your clamps are snug and then climb a freaking mountain.

 

Anyone who suggests that a thermostat does not regulate temperature in an internal combustion engine is out of their mind.

What do you think the damned thing does in winter time? Your radiator would WAYYY overcool your engine without it. It'd never get up to temp. It begins to close in order to decrease coolant flow to the radiator when the engine cools. It begins to open as the temps approach it's rating, until it's fully open. It goes back and forth between the two extremes to regulate temp.

If you have a 180 vs 195 degree thermostat it's not going to make a world of difference or perform some miracle. Yes, the radiator will in effect cool sooner, and cooler temps are good in hot weather. But if you're running 200 degrees, both thermostats are going to be wide open.

The advantage is, when you put a load on the engine, or stress the cooling system, it takes longer to take coolant from 180 to 200+, than it does 195 to 200+. So you DO get the benefit of that little bit of "reserve" capacity, but it's short lived-- if you tax the cooling system for prolonged periods, it won't make one iota difference which thermostat you have, as they are both allowing full flow to the radiator.. In my own opinion, I think in these engines, every little bit helps. There's been several studies which show very little difference in combustion efficiency between 180 and 195 degrees.

Best I can explain it, I'm by no means the expert-- but I see a lot of misinformation being spread around this thread.

 

This has all been very informative. I will plan on putting in the thermostat when it comes in tomorrow. It cant hurt to have a reliable thermostat installed before this very slow and careful trek across America. I am not expecting magic just goaling for some form of reliability. Having come from a back ground of cars that are prone to overheating and engine implosion (rx7's) it just makes sense to me to have a cooling system in tip top shape.

 

Having said that, I have a habit of falling in love with the worst cars on your wallet.

 

The people that disregard this exact statement are the ones shucking out 4k in repairs and swearing off Rovers for life. I'm convinced I won't be one of them My Rover has been nothing but good to me (granted I did a lot of preventative maintenance when I bought it), have put about 12k on it so far (118k total miles now) and zero troubles, not even a hiccup. [knock on wood]. Overbuilt beast of a SUV in my opinion, love taking this thing off-road.

Treat it well and it will do the same.

 

Well magic or not the grey genuine thermostat is the way to go. I didn't get a 20 degree drop off my base temps but will happily take a 6 degree drop sitting in stop and go traffic with the a/c on. No one should be buying the motorad thermostats. Its just not worth the hassle. Thanks everyone for all the good info and help.

 

good luck